Robert H Pietrzak

The Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia

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Publications (144)599.76 Total impact

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    ABSTRACT: Background Population-based data are lacking on the prevalence and comorbidity of subsyndromal depression (SSD) and its associated risk for incident psychiatric disorders in older adults. Methods Using nationally representative data from 10,409 US adults aged 55 years and older who participated in the National Epidemiologic Survey on Alcohol and Related Conditions, we evaluated associations between lifetime SSD at Wave 1, and lifetime and incident mood, anxiety, and substance use disorders over a 3-year period. Results Some 13.8% of older adults met criteria for SSD, and 13.7% met criteria for major depressive disorder (MDD). After adjustment for sociodemographic characteristics, older adults with SSD at Wave 1 had significantly increased odds of lifetime mood (adjusted odds ratios (AORs) = 3.65–10.55), anxiety (AORs = 1.61–2.50), and any personality (AOR = 1.62) disorders. After adjustment for sociodemographic characteristics and comorbid psychiatric disorders, older adults with SSD at Wave 1 had significantly increased odds of developing new-onset MDD (AOR = 1.44, 95% confidence interval (CI) = 1.01–2.05), as well as an anxiety disorder (AOR = 1.52, 95% CI = 1.04–2.20) at Wave 2. Conclusion In addition to the 13.7% of US older adults with lifetime MDD, an additional 13.8% have lifetime SSD, which is not a formally recognized diagnosis. In addition to its high prevalence, SSD is associated with elevated rates of comorbid mood, anxiety, and personality disorders, as well as the development of a new-onset MDD and anxiety disorder. These results underscore the importance of dimensional approaches to assessing depressive symptoms in older persons, as diagnostic approaches that rely on rigorous categorical classifications may fail to identify a substantial proportion of at-risk individuals.
    International Journal of Geriatric Psychiatry 10/2014; · 3.09 Impact Factor
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    ABSTRACT: Accumulation of β-amyloid (Aβ) in the brain is associated with memory decline in healthy individuals as a prelude to Alzheimer’s disease (AD). Genetic factors may moderate this decline. We examined the role of apolipoprotein E (ε4 carrier[ε4+], ε4 non-carrier[ε4−]) and brain-derived neurotrophic factor (BDNFVal/Val, BDNFMet) in the extent to which they moderate Aβ-related memory decline. Healthy adults (n=333, Mage=70 years) enrolled in the Australian Imaging, Biomarkers and Lifestyle study underwent Aβ neuroimaging. Neuropsychological assessments were conducted at baseline, 18-, 36- and 54-month follow-ups. Aβ positron emission tomography neuroimaging was used to classify participants as Aβ− or Aβ+. Relative to Aβ−ε4−, Aβ+ε4+ individuals showed significantly faster rates of cognitive decline over 54 months across all domains (d=0.40–1.22), while Aβ+ε4− individuals showed significantly faster decline only on verbal episodic memory (EM). There were no differences in rates of cognitive change between Aβ−ε4− and Aβ−ε4+ groups. Among Aβ+ individuals, ε4+/BDNFMet participants showed a significantly faster rate of decline on verbal and visual EM, and language over 54 months compared with ε4−/BDNFVal/Val participants (d=0.90–1.02). At least two genetic loci affect the rate of Aβ-related cognitive decline. Aβ+ε4+/BDNFMet individuals can expect to show clinically significant memory impairment after 3 years, whereas Aβ+ε4+/BDNFVal/Val individuals can expect a similar degree of impairment after 10 years. Little decline over 54 months was observed in the Aβ− and Aβ+ ε4− groups, irrespective of BDNF status. These data raise important prognostic issues in managing preclinical AD, and should be considered in designing secondary preventative clinical trials.
    Molecular Psychiatry 10/2014; · 15.15 Impact Factor
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    ABSTRACT: ABSTRACT Background: While it is well known that posttraumatic stress disorder (PTSD) is characterized by heterogeneous symptom clusters, little is known about predominant typologies of PTSD symptoms in older adults. Methods: Latent profile analyses (LPAs) were employed to evaluate predominant typologies of PTSD symptoms in a sample of 164 treatment-seeking older adults with childhood war-related trauma. Multinomial logistic regressions were conducted to evaluate predictors of class membership. Results: LPAs revealed that a 3-class solution best fit the data. These included an Intermediate Disturbance class (50.0%) and two Pervasive Disturbance classes, which differed with respect to severity of avoidance symptoms (Pervasive Disturbance-Low Avoidance: 33.5%, Pervasive Disturbance-High Avoidance: 16.5%). A greater number of traumatic events predicted membership in the Pervasive Disturbance classes. The Pervasive Disturbance-Low Avoidance class had a higher level of education than the Pervasive Disturbance-High Avoidance class. Compared to the Intermediate Disturbance class, the Pervasive Disturbance classes had the highest levels of depression, anxiety and somatization symptoms. Conclusion: These results suggest that PTSD in treatment-seeking older adults may be characterized by three predominant typologies, which are differentiated by overall severity and avoidance symptoms, lifetime trauma burden, education level, and comorbid depression, anxiety, and somatization symptoms. These results underscore the importance of considering heterogeneity in the phenotypic presentation of PTSD in assessment and treatment approaches for this disorder in older adults.
    International psychogeriatrics / IPA. 09/2014;
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    ABSTRACT: Background There has been growing interest in the relation between anxiety disorders and physical conditions in the general adult population. However, little is known about the nature of this association in older adults. Understanding the complex relationship between these disorders can help to inform prevention and treatment strategies unique to this rapidly growing segment of the population. Methods A total of 10,409 U.S. adults aged 55 + participated in Wave 1 (2001–2002) and Wave 2 (2004–2005) of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). Lifetime and past-year DSM-IV anxiety, mood, and substance use disorders, and lifetime personality disorders, were assessed in both waves. Participants self-reported on whether they had been diagnosed by a healthcare professional with a broad range of physical health conditions; this study focuses on cardiovascular disease, gastrointestinal disease, and arthritis. Multivariable logistic regressions adjusted for sociodemographics, comorbid mental disorders, and number of physical health conditions assessed: (1) the relation between past-year physical conditions at Wave 1 and incident past-year anxiety disorders at Wave 2 and; (2) the relation between individual lifetime anxiety disorders at Wave 1 and incident physical conditions at Wave 2. A second set of adjusted multinomial logistic regressions examined Wave 1 sociodemographic and physical and mental health risk factors associated with incident physical condition alone, anxiety disorder alone, and comorbid anxiety and physical condition at Wave 2. Results Past-year arthritis at Wave 1 was significantly associated with increased odds of incident generalized anxiety disorder at Wave 2. Further, any lifetime anxiety disorder and posttraumatic stress disorder at Wave 1 were significantly associated with increased odds of incident gastrointestinal disease at Wave 2. Differential sociodemographic and physical and mental health predictors were significantly associated with increased odds of incident comorbid anxiety disorder and physical conditions. Conclusion Results of the current study elucidate the longitudinal bidirectional relationships between anxiety disorders and physical health conditions in a large, nationally representative sample of older adults. These results have important implications for identifying at risk older adults, which will not only impact this growing segment of the population directly, but will also potentially lessen burden on the healthcare system as a whole.
    Experimental Gerontology 09/2014; · 3.91 Impact Factor
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    ABSTRACT: Exposure to trauma increases the risk for developing threat (ie, fear) symptoms, such as reexperiencing and hyperarousal symptoms, and loss (ie, dysphoria) symptoms, such as emotional numbing and depressive symptoms. While preclinical data have implicated the activated dynorphin/κ-opioid receptor (KOR) system in relation to these symptoms, the role of the KOR system in mediating these phenotypes in humans is unknown. Elucidation of molecular targets implicated in threat and loss symptoms is important because it can help inform the development of novel, mechanism-based treatments for trauma-related psychopathology.
    JAMA Psychiatry 09/2014; · 12.01 Impact Factor
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    ABSTRACT: The aim of this study was to elucidate the dimensional structure of posttraumatic stress disorder (PTSD) and potential moderators and functional correlates of this structure in disaster-affected adolescents. A population-based sample of 2000 adolescents aged 12-17 years (M = 14.5 years; 51% female) completed interviews on post-tornado PTSD symptoms, substance use, and parent-adolescent conflict between 4 and 13 months (M = 8.8, SD = 2.6) after tornado exposure. Confirmatory factor analyses revealed that all models fit well but a 5-factor dysphoric arousal model provided a statistically significantly better representation of adolescent PTSD symptoms compared to 4-factor dysphoria and emotional numbing models. There was evidence of measurement invariance of the dysphoric arousal model across gender and age, although girls and older adolescents aged 15-17 years had higher mean scores than boys and younger adolescents aged 12-14 years, respectively, on some PTSD dimensions. Differential magnitudes of association between PTSD symptom dimensions and functional correlates were observed, with emotional numbing symptoms most strongly positively associated with problematic substance use since the tornado, and dysphoric arousal symptoms most strongly positively associated with parent-adolescent conflict; both correlations were significantly larger than the corresponding correlations with anxious arousal. Taken together, these results suggest that the dimensional structure of tornado-related PTSD symptomatology in adolescents is optimally characterized by five separate clusters of re-experiencing, avoidance, numbing, dysphoric arousal, and anxious arousal symptoms, which showed unique associations with functional correlates. Findings emphasize that PTSD in disaster-exposed adolescents is not best conceptualized as a homogenous construct and highlight potential differential targets for post-disaster assessment and intervention.
    Journal of psychiatric research. 09/2014;
  • Jack Tsai, Julia M Whealin, Robert H Pietrzak
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    ABSTRACT: Objectives. We (1) compared use of various health services nationally between Asian American and Pacific Islander (AA/PI) veterans and veterans of other racial/ethnic groups and (2) specifically compared perceived barriers and stigma related to mental health services. Methods. Using bivariate and multivariable statistics, we analyzed a population-weighted sample of 8315 veterans from the 2010 National Survey of Veterans and a random sample of 567 recent veterans from Hawaii. Results. A total of 1.5% of veterans were AA/PI compared with 0.4% a decade ago. Compared with other veterans, AA/PI veterans reported higher socioeconomic status and better mental health, although these findings may be specific to AA veterans. Adjusting for sociodemographic and health differences, we found no differences in health service use or perceived barriers or stigma related to mental health services. Conclusions. AA/PIs are a small but fast-growing racial/ethnic group within the veteran population that deserves attention. Although veteran status may be protective against some barriers to mental health care found in the general AA/PI population, efforts to reduce barriers to health care among veterans should be continued.
    American journal of public health. 09/2014; 104 Suppl 4:S538-47.
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    ABSTRACT: Background: The detection of early Alzheimer's disease (AD) can rely on subjective and informant reports of cognitive impairment. However, relationships between subjective cognitive impairment, objectively measured cognitive function, and amyloid-β (Aβ) biomarkers remain unclear. Objective: To determine the extent to which impairment or decline in subjective and informant rated cognitive impairment was associated with memory in healthy older adults with high Aβ. Methods: Healthy older adults (n = 289) enrolled in the Australian Imaging, Biomarkers and Lifestyle (AIBL) study were studied at baseline. Pittsburgh Compound B was used to determine Aβ status at baseline. At baseline and 18 months assessments, subjective memory impairment was assessed using the Memory Complaint Questionnaire and the Short Form of the Informant Questionnaire on Cognitive Decline in the Elderly. Cognition was measured using the Cogstate Brief Battery. Results: At baseline, there were no differences between low and high Aβ groups in subjective or informant-rated cognitive impairment, depressive and anxiety symptoms, or cognitive function. Longitudinal analyses showed moderate decline in learning and working memory over the 18 months in the high Aβ group. However there was no change over time in subjective or informant-rated cognitive impairment, depressive and anxiety symptoms, or cognition in either Aβ group. Conclusions: Although healthy older adults with high Aβ levels show decline in learning and working memory over 18 months, subjective or informant ratings of cognitive impairment do not change over the same period suggesting subjective cognitive impairment may have limited utility for the very early identification of AD.
    Journal of Alzheimer's disease: JAD 08/2014; · 4.17 Impact Factor
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    ABSTRACT: Trauma-focused cognitive behavioral treatments are known to be effective for posttraumatic stress disorder (PTSD) in adults. However, evidence for effective treatments for older persons with PTSD, particularly elderly war trauma survivors, is scarce. In an open trial, 30 survivors of World War II aged 65 to 85 years (mean, 71.73 years; SD, 4.8; n = 17 women) with PTSD symptoms were treated with a Web-based, therapist-assisted cognitive-behavioral/narrative therapy for 6 weeks. Intent-to-treat analyses revealed a significant decrease in PTSD severity scores (Cohen's d = 0.43) and significant improvements on secondary clinical outcomes of quality of life, self-efficacy, and posttraumatic growth from pretreatment to posttreatment. All improvements were maintained at a 3-month follow-up. The attrition rate was low (13.3%), with participants who completed the trial reporting high working alliance and treatment satisfaction. Results of this study suggest that integrative testimonial therapy is a well accepted and potentially effective treatment for older war trauma survivors experiencing PTSD symptoms.
    The Journal of nervous and mental disease. 08/2014;
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    Becca R Levy, Corey E Pilver, Robert H Pietrzak
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    ABSTRACT: Older military veterans are at greater risk for psychiatric disorders than same-aged non-veterans. However, little is known about factors that may protect older veterans from developing these disorders. We considered whether an association exists between the potentially stress-reducing factor of resistance to negative age stereotypes and lower prevalence of the following outcomes among older veterans: suicidal ideation, anxiety, and posttraumatic stress disorder (PTSD). Participants consisted of 2031 veterans, aged 55 or older, who were drawn from the National Health and Resilience in Veterans Study, a nationally representative survey of American veterans. The prevalence of all three outcomes was found to be significantly lower among participants who fully resisted negative age stereotypes, compared to those who fully accepted them: suicidal ideation, 5.0% vs. 30.1%; anxiety, 3.6% vs. 34.9%; and PTSD, 2.0% vs. 18.5%, respectively. The associations followed a graded linear pattern and persisted after adjustment for relevant covariates, including age, combat experience, personality, and physical health. These findings suggest that developing resistance to negative age stereotypes could provide older individuals with a path to greater mental health.
    Social science & medicine (1982). 07/2014; 119C:170-174.
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    ABSTRACT: Background / Purpose: Exposure to trauma increases risk of developing threat-related symptomatology such as re-experiencing, avoidance, and hyperarousal, as well as loss-related symptomatology such as emotional numbing, dysphoric apathy and generalized anxiety. Preclinical data has implicated the activated dynorphin/κ-opioid receptor (KOR) system in relation to these symptoms. To date, the role of this system in mediating the phenotypic expression of threat and loss symptomatology in humans is unknown. Main conclusion: These findings suggest the corticotropin-releasing factor (CRF) and KOR systems are both linked to loss-related symptomatology in humans. In addition, elevated cortisol levels partially account for the observed direct relation between KOR availability in an amygdala-anterior cingulate cortex-ventral striatal circuit and severity of loss-related symptomatology.
    69th Society of Biological Psychiatry Annual Meeting 2014; 06/2014
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    ABSTRACT: Background There is increasing recognition that, in addition to negative psychological consequences of trauma such as post-traumatic stress disorder (PTSD), some individuals may develop post-traumatic growth (PTG) following such experiences. To date, however, data regarding the prevalence, correlates and functional significance of PTG in population-based samples are lacking. Method Data were analysed from the National Health and Resilience in Veterans Study, a contemporary, nationally representative survey of 3157 US veterans. Veterans completed a survey containing measures of sociodemographic, military, health and psychosocial characteristics, and the Posttraumatic Growth Inventory-Short Form. Results We found that 50.1% of all veterans and 72.0% of veterans who screened positive for PTSD reported at least ‘moderate’ PTG in relation to their worst traumatic event. An inverted U-shaped relationship was found to best explain the relationship between PTSD symptoms and PTG. Among veterans with PTSD, those with PTSD reported better mental functioning and general health than those without PTG. Experiencing a life-threatening illness or injury and re-experiencing symptoms were most strongly associated with PTG. In multivariable analysis, greater social connectedness, intrinsic religiosity and purpose in life were independently associated with greater PTG. Conclusions PTG is prevalent among US veterans, particularly among those who screen positive for PTSD. These results suggest that there may be a ‘positive legacy’ of trauma that has functional significance for veterans. They further suggest that interventions geared toward helping trauma-exposed US veterans process their re-experiencing symptoms, and to develop greater social connections, sense of purpose and intrinsic religiosity may help promote PTG in this population.
    Psychological Medicine 06/2014; · 5.59 Impact Factor
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    ABSTRACT: Boxing requires agility and manual dexterity, which is associated with fast reflexes and reaction time. This study evaluated the relation between reaction times on cognitive tasks and competition outcomes in boxers. The design was a prospective cohort study. Participants were collegiate amateur boxers who won at least one bout in a single elimination tournament. Optimal pre-participation performance using a computerized cognitive assessment tool (CCAT, Axon Sports) and no significant deterioration in cognitive performance within 24 hours post-bout was required to compete in future bouts. Winners were assumed to be motivated to perform optimally on testing. Performance on speed and accuracy measures were compared in winning and non-winning boxers. Pre-competition minutes of sparring and tournament seedings were recorded. There were 96 eligible boxers who won at least one of 160 bouts. The mean age was 21.3 (SD 1.9) years (range 18.5-29.7). A significant improvement in mean reaction times as a function of advancement in the boxing tournament was observed. The 18 winning boxers who advanced to the finals had significantly faster mean reaction times at the baseline assessment before the competition began (speed composite z-score F(1,94)=4.14, P<0.05, effect size 0.54). Winners also had more sparring experience (Mann-Whitney U=302.5, P<0.001) and higher pre-competition rankings (Mann-Whitney U=288.5, P<0.001). In highly motivated amateur boxers, finalists performed significantly faster than those who failed to reach the finals on measures of pre-competition reaction time. These findings suggest that winners of boxing tournaments might be predicted using pre-competition measures of processing speed.
    The Journal of sports medicine and physical fitness 06/2014; 54(3):340-6. · 0.73 Impact Factor
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    ABSTRACT: Sexual trauma during military service is increasingly recognized as a substantial public health problem and is associated with detrimental effects on veteran mental health. In this study, we examined associations between childhood trauma, military sexual trauma (MST), combat exposure, and military-related posttraumatic stress symptomatology (PTSS) in the Women Veterans Cohort Study (WVCS), a community-based sample of veterans who served in the recent conflicts in Iraq and Afghanistan.
    The Journal of clinical psychiatry. 06/2014; 75(6):637-643.
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    ABSTRACT: OBJECTIVES: Suicide in recent veterans is an international concern. An association between mental disorders and suicide has been established, but less information is available about an association between physical health problems and suicide among veterans. This study extends this area of inquiry by examining the relationship of both physical and mental health problems with suicidal ideation in a representative national sample of Canadian veterans. METHODS: Subjects were a stratified random sample of 2,658 veterans who had been released from the Canadian Armed Forces Regular Force during 1998-2007 and had participated in the 2010 Survey on Transition to Civilian Life. Associations between physical and mental health and past-year suicidal ideation were explored in multivariable regression models using three measures of physical and mental health. RESULTS: The prevalence of suicidal ideation was 5.8% (95% confidence interval [CI]: 5.0%-6.8%). After adjustment for covariates, ideation was associated with gastrointestinal disorders (adjusted odds ratio [AOR] 1.66, CI: 1.03-2.65), depression or anxiety (AOR 5.06, CI: 2.97-8.62) and mood disorders (AOR 2.91, CI: 1.67-5.07); number of physical (AOR 1.22, CI: 1.05-1.42) and mental conditions (AOR 2.32, CI: 2.01-2.68); and SF-12 Health Survey physical health (AOR 0.98, CI: 0.96-0.99 for each 1 point increase) and mental health (AOR 0.88, CI: 0.87-0.89). CONCLUSIONS: Physical health was independently associated with suicidal ideation after adjustment for mental health status and socio-demographic characteristics. The findings underscore the importance of considering physical health in population-based suicide prevention efforts and in mitigating suicide risk in individual veterans.
    Canadian journal of public health. Revue canadienne de santé publique 05/2014; 105(2):e109-115. · 1.02 Impact Factor
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    ABSTRACT: Attentional bias to threat is a key endophenotype that contributes to the chronicity of trauma-related psychopathology. However, little is known about the neurobiology of this endophenotype and no known in vivo molecular imaging study has been conducted to evaluate candidate receptor systems that may be implicated in this endophenotype or the phenotypic expression of trauma-related psychopathology, which is comprised of threat (i.e., re-experiencing, avoidance, and hyperarousal) and loss (i.e., emotional numbing, depression/dysphoria, generalized anxiety) symptomatology. Using the radioligand [(11)C]OMAR and positron emission tomography (PET), we evaluated the relationship between in vivo cannabinoid receptor type 1 (CB1) receptor availability in the amygdala, and performance on a dot-probe measure of attentional bias to threat, and clinician interview-based measures of trauma-related psychopathology. The sample was comprised of adults presenting with a broad spectrum of trauma-related psychopathology, ranging from non-trauma-exposed, psychiatrically healthy adults to trauma-exposed adults with severe trauma-related psychopathology. Results revealed that increased CB1 receptor availability in the amygdala was associated with increased attentional bias to threat, as well as increased severity of threat, but not loss, symptomatology; greater peripheral anandamide levels were associated with decreased attentional bias to threat. A mediation analysis further suggested that attentional bias to threat mediated the relationship between CB1 receptor availability in the amygdala and severity of threat symptomatology. These data substantiate a key role for compromised endocannabinoid function in mediating both the endophenotypic and phenotypic expression of threat symptomatology in humans. They further suggest that novel pharmacotherapies that target the CB1 system may provide a more focused, mechanism-based approach to mitigating this core aspect of trauma-related psychopathology.Neuropsychopharmacology accepted article preview online, 13 May 2014; doi:10.1038/npp.2014.110.
    Neuropsychopharmacology: official publication of the American College of Neuropsychopharmacology 05/2014; · 8.68 Impact Factor
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    ABSTRACT: The aim of the study was to compare the long-term effects of conflict-related sexual violence experienced at the end of World War II (WWII) with non-sexual WWII trauma (e.g., being exposed to shell shock or physical violence). A total of 27 elderly wartime rape survivors were compared to age- and gender-matched control subjects who were drawn from a larger sample of subjects over 70 years of age who had experienced WWII-related trauma. A modified version of the Posttraumatic Diagnostic Scale was used to assess trauma characteristics and posttraumatic stress disorder (PTSD) symptoms and the Brief Symptom Inventory-18 was used to assess current psychopathology. Additionally, measures of posttraumatic growth (Posttraumatic Growth Inventory) and social acknowledgement as a trauma survivor (Social Acknowledgement Questionnaire) were used to assess two mediating variables in post-trauma conditions of rape victims. Women exposed to conflict-related sexual violence reported greater severity of PTSD-related avoidance and hyperarousal symptoms, as well as anxiety, compared with female long-term survivors of non-sexual WWII trauma. The vast majority (80.9 %) of these women also reported severe sexual problems during their lifetimes relative to 19.0 % of women who experienced non-sexual war trauma. Women exposed to conflict-related sexual violence also reported greater posttraumatic growth, but less social acknowledgement as trauma survivors, compared to survivors of non-sexual war trauma. The results were consistent with emerging neurobiological research, which suggests that different traumas may be differentially associated with long-term posttraumatic sequelae in sexual assault survivors than in other survivor groups and highlights the need to treat (or better prevent) deleterious effects of conflict-related sexual violence in current worldwide crisis zones.
    Archives of Sexual Behavior 03/2014; · 3.53 Impact Factor
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    ABSTRACT: Although beta-amyloid, anxiety and depression have been linked cross-sectionally to reduced memory function in healthy older adults without dementia, prospective data evaluating these associations are lacking. Using data from an observational cohort study of 178 healthy older adults without dementia followed for 3 years, we found that anxiety symptoms significantly moderated the relationship between beta-amyloid level and decline in verbal (Cohen's d = 0.65) and episodic (Cohen's d = 0.38) memory. Anxiety symptoms were additionally linked to greater decline in executive function, irrespective of beta-amyloid and other risk factors. These findings suggest that interventions to mitigate anxiety symptoms may help delay memory decline in otherwise healthy older adults with elevated beta-amyloid.
    The British journal of psychiatry: the journal of mental science 02/2014; · 6.62 Impact Factor
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    ABSTRACT: There is considerable public and professional concern about the mental health status of veterans deployed to Iraq and Afghanistan as well as how to engage and retain symptomatic veterans in treatment. This study examined demographic, psychiatric, and psychosocial determinants of prospective initiation and retention in mental health services among symptomatic Iraq/Afghanistan veterans. One hundred thirty-seven symptomatic veterans who were referred to mental health screening completed a survey at the time of their first mental health visit. Associations between survey variables and subsequent Veterans Affairs service utilization were evaluated. The most consistent determinants of mental health service initiation and retention were severity of posttraumatic stress disorder (PTSD) and depressive symptoms. Notably, whereas PTSD-related re-experiencing symptoms were independently associated with initiation of mental health treatment, PTSD-related numbing symptoms were independently associated with retention in treatment. Stigma, barriers to care, and beliefs about mental health treatment were not associated with either mental health initiation or retention.
    The Journal of nervous and mental disease 02/2014; 202(2):97-104. · 1.77 Impact Factor
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    ABSTRACT: OBJECTIVE: Cross-sectional genetic association studies have reported equivocal results on the relationship between the brain-derived neurotrophic factor (BDNF) Val66Met and risk of Alzheimer's disease (AD). As AD is a neurodegenerative disease, genetic influences may become clearer from prospective study. We aimed to determine whether BDNF Val66Met polymorphism influences changes in memory performance, hippocampal volume, and Aβ accumulation in adults with amnestic mild cognitive impairment (aMCI) and high Aβ. METHODS: Thirty-four adults with aMCI were recruited from the Australian, Imaging, Biomarkers and Lifestyle (AIBL) Study. Participants underwent PiB-PET and structural MRI neuroimaging, neuropsychological assessments and BDNF genotyping at baseline, 18 month, and 36 month assessments. RESULTS: In individuals with aMCI and high Aβ, Met carriers showed significant and large decline in episodic memory (d = 0.90, p = .020) and hippocampal volume (d = 0.98, p = .035). BDNF Val66Met was unrelated to the rate of Aβ accumulation (d = -0.35, p = .401). CONCLUSIONS: Although preliminary due to the small sample size, results of this study suggest that high Aβ levels and Met carriage may be useful prognostic markers of accelerated decline in episodic memory, and reductions in hippocampal volume in individuals in the prodromal or MCI stage of AD.
    PLoS ONE 01/2014; 9(1):e86498. · 3.53 Impact Factor

Publication Stats

2k Citations
599.76 Total Impact Points

Institutions

  • 2014
    • The Florey Institute of Neuroscience and Mental Health
      Melbourne, Victoria, Australia
    • United States Department of Veterans Affairs
      Bedford, Massachusetts, United States
  • 2009–2014
    • Yale University
      • • Department of Diagnostic Radiology and Pediatric Diagnostic Radiology
      • • Department of Psychiatry
      New Haven, Connecticut, United States
    • Yale-New Haven Hospital
      • Department of Laboratory Medicine
      New Haven, Connecticut, United States
    • RMIT University
      Melbourne, Victoria, Australia
  • 2013
    • University of Greifswald
      • Department of Psychiatry and Psychotherapy
      Greifswald, Mecklenburg-Vorpommern, Germany
    • University of Hawaiʻi at Hilo
      Hilo, Hawaii, United States
    • University of Manitoba
      Winnipeg, Manitoba, Canada
  • 2008–2013
    • University of Melbourne
      • • Department of Psychiatry
      • • Melbourne School of Psychological Sciences
      Melbourne, Victoria, Australia
    • Alpert Medical School - Brown University
      • Department of Pediatrics
      Providence, RI, United States
  • 2011
    • Naval Health Research Center
      • Department of Warfighter Performance
      San Diego, CA, United States
    • Melbourne Institute of Technology
      Melbourne, Victoria, Australia
    • Georgetown University
      Washington, Washington, D.C., United States
  • 2006–2011
    • University of Connecticut
      • Department of Psychology
      Storrs, CT, United States
  • 2006–2008
    • UConn Health Center
      • • Division of Behavioral Sciences and Community Health
      • • Department of Psychiatry
      Farmington, CT, United States
  • 2005
    • Colby College
      Waterville, Maine, United States